Kristoffer Reitan threatened to blow a five-shot lead before clinging onto a wire-to-wire victory at the Nedbank Golf Challenge in honour of Gary Player.
Reitan left the door open for playing partners Jayden Schaper and Dan Bradbury after an inconsistent start to his final round at Gary Player CC in Sun City, where he mixed four birdies with three bogeys during an eventful front nine.
The Norwegian's bogey at the 15th saw his lead to a single stroke, before a three-par finish closed a level-par 71 to remain on 17 under and secure a second DP World Tour title of 2025.
Reitan - one of 10 players who earned dual membership on the DP World Tour and PGA Tour for next season with their finish in the Race to Dubai standings - finished one ahead of Schaper and Bradbury, with Christiaan Bezuidenhout four strokes back in fourth.
"I don't know what I'm feeling right now," Reitan said after his win. "I had a lot of nerves today. But to get it over the line in the end is a better feeling than I can describe.
"I needed things to go my way a bit as well. Those two guys, Dan and Jayden, they played so well today, they kept pushing me. I was able to keep them at arm's length in the end. I'm definitely proud of myself and I'm happy to be able to say that."
Reitan cancelled out a bogey at the first with a close-range birdie at the next, then responded to a dropped shot at the third by rolling in from 13 feet at the fifth to restore a three-shot cushion.
He failed to get up and down from off the par-three seventh green to save par but closed out his front nine successive birdies, only for Schaper and Bradbury to pile pressure with two birdies in the first three holes of their back nines.
Bradbury moved six under for the day and alongside Schaper on 16 under when he took advantage of the par-five 14th, although neither were able to find any further birdies over the closing stretch to leave Reitan claiming his first title since the Soudal Open in May.
The victory rounded off a sensational day for Scandinavian golf - following Dane Rasmus Neergaard-Petersen's win at the Crown Australian Open - and looks to move him inside the world's top 50.
Bezuidenhout finished on fourth on 13 under and Shaun Norris claimed fifth ahead of Julien Guerrier and Thomas Detry, while England's Andy Sullivan ended in a share of eighth alongside Angel Ayora.
The DP World Tour stays in South Africa for the Alfred Dunhill Championship, held at the Royal Johannesburg Club. Live coverage begins on Thursday from 10am on Your Site Golf. .
